People Focused - Project Driven

WRA is Presenting Seven Papers at NTRB's Upcoming Conference.

May 11th, 2017

The 16th Transportation Research Board National Transportation Planning Applications Conference is being help from May 14 through May 18 in Raleigh, North Carolina.   WRA is proud to announce that four engineers from WRA’s Transportation Planning Group will be presenting seven papers at this conference.

Ashley Tracy, one of WRA’s Transportation Planners, will be presenting the “Development of a Multi-Resolution Network to Support Statewide Modeling and Project Analysis” that focuses on best practices and lessons learned for developing multi-resolution networks, based on experience with Delaware Department of Transportation (DelDOT) and Maryland State Highway Administration.  It will include discussion of the efforts to build a multi-resolution network, appropriate data sources to use, and challenges encountered at each step of the process; such as network routability fixes, the customized GIS Network Builder tool, how to resolve junction control and transit line files, network attribution, composite zone structure and related disaggregated demographic data for each level, centroid connector generation, software limitations, run time implications, and data maintenance. 

The presentation, “Using Transportation to Improve Public Health” will also made by Ashley Tracy.  DelDOT, University of Delaware's Center for Applied Demography & Social Research (CADSR), and the Delaware Division of Public Health are collaborating to develop a process to quantify the impacts of transportation and land use decisions on public health in Delaware. This initiative builds on collaborative efforts and will allow DelDOT to predict active bicycle and pedestrian travel at the statewide level and to use health impacts as new measures of effectiveness (MOE's) for transportation and land use alternatives.

The presentation will include discussion of modifications to the yearly Delaware Travel Monitor Survey to capture previously underreported active transportation and recreational trips. Measures of the built environment, such as an accessibility index, were developed as equations for the Delaware Statewide Peninsula Travel Demand Model to predict and assign active transportation trips on roadway, bike, and pedestrian networks. The model required structural refinements in order to predict shifts in travel mode from passive to active transportation and recreational travel, such as development of an ultra-high resolution travel network based upon the E911 centerline file that is fully routable and includes parcel-level synthetic household demographics, sidewalks and trails.

The final presentation being made by Ashley Tracy is “Point of Dispensing (POD) Model” which is a unique application of a customized evacuation model developed for DelDOT. Points of Dispensing (POD’s) are used to distribute medical countermeasures to a population during a biological hazard outbreak. Emergency planners typically focus on the internal operation of the POD, but fall short in accounting for external factors such as roadway and parking capacity. The POD Model can be used to predict how the travel network might perform in a state of emergency if the public were directed to visit a POD for an antidote.

The presentation will discuss a case study performed for Wilmington, Delaware using five POD’s at publicly accessible locations. This application of a POD model is fundamentally different than a standard evacuation model where people go from one point to another and stay; this application models people converging to the most desirable POD, waiting in line to receive medication, and being released to return home or to work once treated.

Scott Thompson-Graves, Vice-President,  will be presenting “Application of the Maryland Statewide Model – Applications of a Macro Based Capacity Constraint Assignment Technique.”   This presentation will present several case studies that were developed to test the ability of the models to provide Information for non-traditional planning such as determining the impacts and user costs of roadway construction, evaluating small and large scale evacuations, and determining roadway user benefits at the project and system-wide level.

The first application is an Evacuation Model developed for SHA. The Model provides the user the opportunity to define both the evacuation area as well where the evacuees need to travel to along with other parameters including evacuation departure times, State of Emergency regions and factors for controlling the response rates and auto occupancy.  The Evacuation Model uses a capacity constraint process to monitor those links where the volume exceeds the jam capacity.  A second application of the capacity constraint assignment is a project evaluation model developed to compare a low and high capacity network. The capacity constraint assignment technique is used to further evaluate the networks beyond the macro assignment differences to understand the projects ability to better serve demand in a corridor and reduce congestion levels.  SHA intends to use this tool to measure the impacts of short term road closures and construction capacity reductions.  

“Macro / Meso / Micro Framework and Application on I-395 HOT Lane Conversion” will be presented by Jeffrey Moore, an Associate at WRA.  Often times the regional macroscopic model will be used to create the trip tables for input into the microsimulation model, but given the obvious differences in the assignment process and factors considered, the macro models are rarely able to provide an accurate trip table. To account for this inaccuracy WRA has developed a macro / meso / micro framework that utilizes the regional model and uses mesoscopic assignments and ODME to create a calibrated trip table suitable for use in microsimulation.  This framework was recently applied to the I-395 HOT Lane Conversion project in the Northern Virginia Region. 

This presentation will present the approach taken to develop the microsimulation models used for the Interchange Justification Report to support the project and how it was developed from the MWCOG Regional Travel Demand Model and a VISUM Meso-scopic strudy area model that was used with ODME (TFLowFuzzy) to generate the calibrated trip tables.  The use of the Mesoscopic assignment provides an effective framework for the efficient development of operational level trip tables that are based on regional model forecasts. 

Jonathan Avner, a Senior Project Planner from WRA, will be making two presentations.  The first is titled, “Slugging in the I-395 Corridor”  Over the past several years informal ride sharing has become more prevalent in the Washington DC region and in some areas has become a formalized mode.  One such example is the I-395 Corridor where a terminal has been established at the Pentagon to allow for the pickup or drop off of “slugs”. Allow SOV vehicles to “scrape” or pick up passengers allows for the SOV to become HOV3 and thus use the HOV facility in the corridor.  Throughout the I-395 and I-95 corridors, locations have been identified for pickup and drop off locations. 

As part of the I-395 HOT Lane Conversion project, the transfer of SOV to HOV and slugging were incorporated as part of the travel demand modeling and traffic forecasting component.  The presentation will present how the SOV trips were identified and thus converted to HOV through the duration of the corridor.  This shift in mode type only represents the interim leg of the trip as the origin to pickup and drop-off to destination portions are still modeled as SOV.  The presentation will discuss how the calibration of the model and impacts to the base case (2015) and forecast build and no-build scenarios. 

Jonathan’s second presentation is the “Development of New Supply Models Using Big Data in Maryland.”  Maryland State Highway Administration (SHA) maintains its own system to collect and process observed speed data. From this system SHA is able to extract vehicle based speed information on 15 minute intervals on data collected on a cross section of roadways including interstates, expressways and major arterials. 

This presentation will discuss the approach taken to calibrate the volume delay function parameters using the observed speed data from SHA. Challenges of the analysis included defining the input free flow speed and link level capacity as well as dealing with over-saturated conditions. Various approaches were tested and will be presented including the use of model speeds and capacities as well as maximum observed speeds and max flow to represent capacity. The approaches revealed an inconsistency between the model and observed speeds.  This inconsistency resulted in a second goal of the analysis which was to define a new speed and capacity logic that was developed using link level attributes from the Maryland Centerline file and calibrated using the observed speed data. The ability of the MSTM to more accurately represent the true congested speeds on the network is an important contribution to SHA as they are now able to predict several of the performance measures currently only available from existing speed data.  

If you are attending the conference, don't forget to stop by to listen to these presentations.